Studies are proposed to investigate the photomyoclonic syndrome in the baboon, Papio papio, using electrophysiological and lesioning techniques. The action of classical and new anticonvulsant agents will be studied in single and chronic dosage schedules and EEG patterns as well as evoked potentials at various brain sites will be used to gain clues as to mechanism of anticonvulsive action. A breeding program is proposed to gain insight into genetic mechanisms involved and to provide infant baboons for the study of the development of seizures in the immature animals.